from django.db import models
from django.utils.translation import ugettext_lazy as _
from django.utils import timezone

from core.models import User, Group


class Election(models.Model):
    """
    This class allows to create a new election
    """
    title = models.CharField(_('title'), max_length=255)
    description = models.TextField(_('description'), null=True, blank=True)
    start_candidature = models.DateTimeField(_('start candidature'), blank=False)
    end_candidature = models.DateTimeField(_('end candidature'), blank=False)
    start_date = models.DateTimeField(_('start date'), blank=False)
    end_date = models.DateTimeField(_('end date'), blank=False)

    edit_groups = models.ManyToManyField(
        Group, related_name="editable_elections",
        verbose_name=_("edit groups"), blank=True)

    view_groups = models.ManyToManyField(
        Group, related_name="viewable_elections",
        verbose_name=_("view groups"), blank=True)

    vote_groups = models.ManyToManyField(
        Group, related_name="votable_elections",
        verbose_name=_("vote groups"), blank=True)

    candidature_groups = models.ManyToManyField(
        Group, related_name="candidate_elections",
        verbose_name=_("candidature groups"), blank=True)

    voters = models.ManyToManyField(User, verbose_name=('voters'), related_name='voted_elections')
    archived = models.BooleanField(_("archived"), default=False)

    def __str__(self):
        return self.title

    @property
    def is_vote_active(self):
        now = timezone.now()
        return bool(now <= self.end_date and now >= self.start_date)

    @property
    def is_vote_finished(self):
        return bool(timezone.now() > self.end_date)

    @property
    def is_candidature_active(self):
        now = timezone.now()
        return bool(now <= self.end_candidature and now >= self.start_candidature)

    @property
    def is_vote_editable(self):
        return bool(timezone.now() <= self.end_candidature)

    def can_candidate(self, user):
        for group in self.candidature_groups.all():
            if user.is_in_group(group):
                return True
        return False

    def can_vote(self, user):
        if not self.is_vote_active or self.has_voted(user):
            return False
        for group in self.vote_groups.all():
            if user.is_in_group(group):
                return True
        return False

    def has_voted(self, user):
        return self.voters.filter(id=user.id).exists()

    @property
    def results(self):
        results = {}
        total_vote = self.voters.count()
        for role in self.roles.all():
            results[role.title] = role.results(total_vote)
        return results

    # Permissions


class Role(models.Model):
    """
    This class allows to create a new role avaliable for a candidature
    """
    election = models.ForeignKey(Election, related_name='roles', verbose_name=_("election"))
    title = models.CharField(_('title'), max_length=255)
    description = models.TextField(_('description'), null=True, blank=True)
    max_choice = models.IntegerField(_('max choice'), default=1)

    def results(self, total_vote):
        results = {}
        total_vote *= self.max_choice
        non_blank = 0
        for candidature in self.candidatures.all():
            cand_results = {}
            cand_results['vote'] = self.votes.filter(candidature=candidature).count()
            if total_vote == 0:
                cand_results['percent'] = 0
            else:
                cand_results['percent'] = cand_results['vote'] * 100 / total_vote
            non_blank += cand_results['vote']
            results[candidature.user.username] = cand_results
        results['total vote'] = total_vote
        if total_vote == 0:
            results['blank vote'] = {'vote': 0, 'percent': 0}
        else:
            results['blank vote'] = {'vote': total_vote - non_blank, 'percent': (total_vote - non_blank) * 100 / total_vote}
        return results

    @property
    def edit_groups(self):
        return self.election.edit_groups

    def __str__(self):
        return ("%s : %s") % (self.election.title, self.title)


class ElectionList(models.Model):
    """
    To allow per list vote
    """
    title = models.CharField(_('title'), max_length=255)
    election = models.ForeignKey(Election, related_name='election_lists', verbose_name=_("election"))

    def __str__(self):
        return self.title


class Candidature(models.Model):
    """
    This class is a component of responsability
    """
    role = models.ForeignKey(Role, related_name='candidatures', verbose_name=_("role"))
    user = models.ForeignKey(User, verbose_name=_('user'), related_name='candidates', blank=True)
    program = models.TextField(_('description'), null=True, blank=True)
    election_list = models.ForeignKey(ElectionList, related_name='candidatures', verbose_name=_('election list'))

    def can_be_edited_by(self, user):
        return (user == self.user) or user.can_edit(self.role.election)

    def __str__(self):
        return "%s : %s" % (self.role.title, self.user.username)


class Vote(models.Model):
    """
    This class allows to vote for candidates
    """
    role = models.ForeignKey(Role, related_name='votes', verbose_name=_("role"))
    candidature = models.ManyToManyField(Candidature, related_name='votes', verbose_name=_("candidature"))

    def __str__(self):
        return "Vote"